1. Field of the Invention
The present invention relates a lamination type electronic component and more particularly, to a lamination type electronic component of an LC filter having a coil disposed inside a laminate made up of laminated insulating layers of ceramic, etc.
2. Description of the Related Art
Up to now, for example, a laminated inductor disclosed in Japanese Unexamined Patent Application Publication No. 2002-64016 is known among such lamination type electronic components. In the laminated inductor, ceramic insulating layers and conductor patterns are alternately laminated, the conductor patterns are stacked one upon another in the lamination direction of the ceramic insulation layers by connecting the end portion of each conductor pattern in order, and a coil in which the direction of the coil axis is in the lamination direction of the ceramic insulating layers is formed within a chip-type ceramic laminate.
In the related lamination type electronic component, when seen from the lamination direction of the ceramic insulating layers, the adjacent conductor patterns are arranged so as to lie one upon the other with a ceramic insulating layer therebetween. In this way, when the conductor patterns adjacent each other are formed so as to lie upon the other with a ceramic insulating layer therebetween, if the ceramic insulating layer is displaced in the lamination of the ceramic insulating layer and the conductor patterns, the opposing area between the adjacent conductor patterns facing each other changes to cause the change of inductance of the coil, and, as a result, the electrical characteristics of the lamination type ceramic electronic component change.
For example, in a LC filter having a capacitor contained in addition to a coil where the conductor patterns are connected in order inside a chip-type ceramic laminate, there is a problem in that the inductance of the coil changes by a change of the facing area between conductor patterns and the frequency of the attenuation pole of the filter changes. Moreover, the lamination displacement inevitably occurs.
In order to solve such a problem contained in the related lamination type ceramic electronic component, for example, as shown in FIG. 10, in an LC filter having quadrilateral spiral conductor patterns 31 and 32 disposed adjacent to each other with a ceramic insulating layer therebetween and having a quadrilateral spiral coil (inductor) L in which the end portions 31a and 32a of the conductor patterns 31 and 32 are electrically connected through a via hole vh formed in the ceramic insulating layer 30, it is considered to form the width of the conductor pattern 31, out of the conductor patterns 31 and 32, narrower than the width of the other conductor pattern 32 and to form the conductor pattern 31 located substantially in the middle in the width direction of the conductor pattern 32. When constructed in this way, even if there are slight variations in location of the conductor patterns 31 and 32 adjacent to each other having the ceramic insulating layer therebetween, the opposing area between the facing conductor patterns 31 and 32 is kept constant.
However, when lamination displacement occurs, for example, as shown in FIG. 10, when the conductor pattern 31 is displaced in the amount of ΔX in the X-axis direction from the conductor pattern 32, a pair of sides 31ya and 31yb extending in the Y-axis direction of the conductor pattern 31 is also shifted in the amount of ΔX in the X-axis direction from a pair of sides 32ya and 32yb extending in the Y-axis direction of the conductor pattern 32. Because of this shift, the space between the inside edge e1a, of the coil L, of the side 31ya of the conductor pattern 31 and the inside edge e2a, of the coil L, of the side 32ya of the conductor pattern 32 is reduced from g to (g−ΔX), and simultaneously, the space between the outer edge e1b, of the coil L, of the side 31yb of the conductor pattern 31 and the outer edge e2b, of the coil L, of the side 32yb of the conductor pattern 32 is also reduced from g to (g−ΔX).
Now, as shown in FIG. 10, in the case where the conductor patterns 31 and 32 are stacked on each other, when the conductor pattern 31 is displaced from the conductor pattern 32, even if displacement occurs where the overlapping width does not change, since the coupling of electric lines of force due to the edge effect is reduced, the inductance value of the coil L decreases.
An edge effect means that the electric lines of force are produced at an edge portion of an electrode so as to spread out. When the coupling between layers of a coil pattern is considered, the electric lines of force from the conductor pattern 31 produced by an edge effect are received by the protruded portion of the conductor pattern 32. However, when the distance between the edges e2a and e1a, and e2b and e1b is reduced, the electric lines of force received by the edges e2a and e2b are reduced. Because of this, the inductance value of the coil L is also reduced. Therefore, when the location of the conductor patterns 31 and 32 is varied, the distance between the edges e2a and e1a, and e2b and e1b is also varied and, as a result, there is a problem in that the inductance value of the coil L is also varied.